Conserved Protein Domain Family
GH18_chitolectin_chitotriosidase

?
cd02872: GH18_chitolectin_chitotriosidase 
Click on image for an interactive view with Cn3D
This conserved domain family includes a large number of catalytically inactive chitinase-like lectins (chitolectins) including YKL-39, YKL-40 (HCGP39), YM1, oviductin, and AMCase (acidic mammalian chitinase), as well as catalytically active chitotriosidases. The conserved domain is an eight-stranded alpha/beta barrel fold belonging to the family 18 glycosyl hydrolases. The fold has a pronounced active-site cleft at the C-terminal end of the beta-barrel. The chitolectins lack a key active site glutamate (the proton donor required for hydrolytic activity) but retain highly conserved residues involved in oligosaccharide binding. Chitotriosidase is a chitinolytic enzyme expressed in maturing macrophages, which suggests that it plays a part in antimicrobial defense. Chitotriosidase hydrolyzes chitotriose, as well as colloidal chitin to yield chitobiose and is therefore considered an exochitinase. Chitotriosidase occurs in two major forms, the large form being converted to the small form by either RNA or post-translational processing. Although the small form, containing the chitinase domain alone, is sufficient for the chitinolytic activity, the additional C-terminal chitin-binding domain of the large form plays a role in processing colloidal chitin. The chitotriosidase gene is nonessential in humans, as about 35% of the population are heterozygous and 6% homozygous for an inactivated form of the gene. HCGP39 is a 39-kDa human cartilage glycoprotein thought to play a role in connective tissue remodeling and defense against pathogens.
Statistics
?
PSSM-Id: 119351
View PSSM: cd02872
Aligned: 63 rows
Threshold Bit Score: 486.681
Threshold Setting Gi: 13537190
Created: 6-Jul-2005
Updated: 17-Jan-2013
Structure
?
Program:
Drawing:
Aligned Rows:
 
active site
Conserved site includes 17 residues -Click on image for an interactive view with Cn3D
Feature 1:active site [active site]
Evidence:
  • Comment:the chitolectins bind chitin but lack the catalytic residues and do not have chitolytic activity, in contrast to the chitotriosidases which are also included in this alignment.
  • Structure:1HKK_A; Human macrophage chitotriosidase binds allosamidin
    View structure with Cn3D
  • Comment:Allosamidin is thought to resemble the structure of a reaction intermediate that is unique among the glycoside hydrolases.
  • Structure:1WAW_A; Human macrophage chitotriosidase binds argadin, a chitinase inhibitor
    View structure with Cn3D

Sequence Alignment
?
Format: Row Display: Color Bits: Type Selection:
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
Feature 1            #   #                                                                        
1HKK_A          3 LVCYFTNWAQYRQGEARFLPKDLDPSLCTHLIYAFAGMTn--hQLSTTEWn-------DETLYQEFNGLKkmnpkLKTLL 73
gi 156408323   23 RVCYFTNWAQYRPDPVKFLPKDIDPLLCTHIVYAFAKIDpatnKIGTYEWn-------DDRLYKEINDLKlknpsLKTLL 95
gi 15292287   125 IVCYYTNWSQYRVKIGKFVPEDIPADLCTHIIFAFGWLKk--nKLSSYESndet-kdnVPGLYERMMTLKkanpkLKILL 201
gi 15292287   560 VFCYLTSWSAKRPGAGKFQPENIDPKLCTHIVYAFATLQ----DYKLTEAtd-----dDPENYESVIALRdnnpdLQILL 630
gi 22003996   473 VVCYFTNWSAKRKGKGHYEPEDIDATLCTHVIYAFANIKe--fKIVPTEPvdegdgsaKKGFWERIVALKtknpqLKVML 550
gi 22003996    46 IVCYFTNWAQYRQGDGKFLPEDIDPTLCTHIIYAFGWMKk--hKLSSFDAaddt-kngKKGLYERVIDLKkknpsLKVLL 122
gi 92110432    24 RVCYYTNWAQYRNGIAKFEPSHIDPSLCTHIIYAFGKLEd--nGITNFEWn-------DETRYVEVNAFKrnntgLKTLL 94
gi 156382333   23 RGCYYTNWSQYRPKGGTFWPEDIDPFLCTHILFSFAKVNqtthKLDIYEEn-------DHELYQRINALKkinpkLKTQI 95
gi 156408091   21 RVCYHTNWSQYRQGRAKFWPEDIPADLCTHLMYSFAKINqk-nELAMYEWn-------DDKLYPRFNALKqknpeLKTLL 92
gi 167830427   41 RVCYYTNWSQYRPGNGKYIPDDVDPFLCTHIVYSFVEIGsn-nQLKLREWn-------GDQLIDSLLTKKqtnpdLLITA 112
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
Feature 1             ##                                        # ##                              
1HKK_A         74 AIGGWNFGtq---kFTDMVATANNRQTFVNSAIRFLRKYSFDGLDLDWEYPgsqg-spavDKERFTTLVQDLANAFQQea 149
gi 156408323   96 AVGGWNHEsgpvspFSQMVASKSNRTTFISSLLQLSDKYDFDGFDLDWEYPasrgnsppqDKQHFTILCEEMLDAFKRka 175
gi 15292287   202 ALGGWSFGtq---kFKDMSSTRYTRQTFVYSAIPFLRKRGFDGLDMDWEYPkg-----sdDKKNFVLLLKELREAFEAea 273
gi 15292287   631 AIGGWAFGst---pFKELTSNVFRMNQFVYEAIDFLRDYKFNGLDVDWEYPrg-----aeDRVAYVSLLKELRVAFEGea 702
gi 22003996   551 AVGGWMLGsa---pFREVTENSYRQSLFVFNAIDFLREKGFDGLDVDWEFPrg-----aeDKKKLAGLIKELRVAFDGeg 622
gi 22003996   123 AVGGWSFGtq---rFKEMASNSYNRRLFIFSALNFLRRRKFDGLDLDWEFPrg-----neDKKNFVELVRELREAFEAea 194
gi 92110432    95 AMGGWTAGsk---pYSDMAASPENRRTFINASISWLRKYDFDGLDMDWEYPanrg-gvpeDFNNFPILLKEILEAFTEea 170
gi 156382333   96 AVGGWTHEekn-spFSKMVATKEKRAIFIKSAIETLRTHGFDGLDLDWEYPgmrggspksDKGRFTLLCRELREAFEAea 174
gi 156408091   93 AVGGWNHEnan-spFSRMVKTAATRKVFIDSVIRILRTWGFDGLDLDWEYPatrggsppeDKQRFTVLCQELMNTFIAeg 171
gi 167830427  113 AVGGWNFGte---rFTAVCENEANMRMFAKTSVDFLRQFKFDGLDMDWEYPgsrg-sppeDKQRFTRLLEILMEEYEAea 188
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
Feature 1                        ##                      # ##    #                                
1HKK_A        150 qtsgkerLLLSAAVPAGqtyVDAGYEVDKIAQNLDFVNLMAYDFHGSWe-kVTGHNSPLYkrqeqsg-----aaaslnvD 223
gi 156408323  176 adtdkprMLLTAAVSAGhgtVDAAYEVHKLAGILDWINLMTYDLHGPWe-pYTGHHTALVgppgd----------kltvS 244
gi 15292287   274 qelkkprLLLSAAVPVGpdnIRGGYDVPAIASYLDFINLMAYDFHGKWe-rETGHNAPLYapstdse-----wrkqlsvD 347
gi 15292287   703 kssglprLLLTAAVPASfeaIAAGYDVPEISKYLDFINVMTYDFHGQWe-rTVGHNSPLFalesatg-----yqkkltvD 776
gi 22003996   623 laskkprLILSMAAPASfeaISAGYDVEELNKHVDMINMMTYDFHGDWe-rQVGHHSPLFplytass-----fqkkltvD 696
gi 22003996   195 kekklprLLLTAAVSAGaetIRGGYDVPAVAAYVDFLNVMSYDFHGKWe-sMTGHNSPLYaqanett-----wrkqlcmD 268
gi 92110432   171 ktsgksrLLLTAAVGVGksvADTAYNIPEMSKYLDFISLMAYDLRGGWe-kTTGFNAALYrssads-------sdeynvA 242
gi 156382333  175 kasgkerMLLTAAVAAGlwtIKGAYDIADIAEPLDWINLMTYDLHGTWe-yKTGHHTAMGpdgdkltlpfaiwywmnnrD 253
gi 156408091  172 kqtgkprLLLTAAVSAGkntIDKAYEVEKIGKILDLINLMAYDLRGKWe-pHTGHHTSLEgppge----------iltvK 240
gi 167830427  189 lstgnprLLLTAAVPAGpstIEAGFEINAVCSILDLVHIMTYDFHGGSwekNTGHNAALYpsppgti------qndfniE 262
                         250       260       270       280       290       300       310       320
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
Feature 1                               # #                            #                          
1HKK_A        224 AAVQQWLQKGTPASKLILGMPTYGRSFTLasss-dtrvGAPATGSGTPGPFTKEGGMLAYYEVCsw---kgATKQRIQDq 299
gi 156408323  245 YAVKYWMEKGMPCGKIALGMANYGHAFEL---------SDPTKTALGAPANVNKGRSYPYYELCkl----pLTKVTDNPa 311
gi 15292287   348 NAASLWVKMGAPKEKLVIGMPTYGRSFTLanpd-khgpNAPASGGGREGVYTKEGGFLAYYEICeml-lngAVYVWDDEm 425
gi 15292287   777 YSAREWVKQGAPKEKLLIGMPTYGRSFELvndt-qfdiGSPSSGGGKAGKFTNEAGFLSYYEVCsflaadnTTLVWDSEq 855
gi 22003996   697 YSAGEWVRKGASKEKLLVGIPTYGRTFTLgdnn-ltdvGAPATAGGRPGNYTGETGFLSFFEICdll-rsgATLVWDNEq 774
gi 22003996   269 FGVKTWERLGAPKEKIVVGTGTYGRTFTLanpn-nngmNAPSSGGGDAGQFTKEAGFLAYYEICdml-kkgADYVWDEEq 346
gi 92110432   243 FAVDYWLRKGTPKEKLILGLATYGRSFKLqden-nfgvGAPATGAGPQGKYVAEDGFLPYYDICarqvqrvGETYRDEKa 321
gi 156382333  254 TWEKPGIRKGMPANKIVLGLATYGRAFGLpspatngldSARDYQYTPKGKYTDAEGFLAYYEICkr----gLTVVHKNKa 329
gi 156408091  241 FATQYWIDMGAPPSKIALGLGTYGRSFKLtfke-kngiGAPANGNPPRGPYTRESGFLSYYEICdmmpkmkTMKTDQSEv 319
gi 167830427  263 ESVNIWLTNGCDPKKLVLGVPTYGRTYTLldpl-kfgfGANATGPGDAGTYTREAGFLAYYEICpymndpaANFIWSDYa 341
                         330       340       350       360       370       380       390
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
Feature 1                                                   #                            
1HKK_A        300 KVPYIFr----dNQWVGFDDVESFKTKVSYLKQ-KGLGGAMVWALDLDDFAGfsCNq-gRYPLIQTLRQEL 364
gi 156408323  312 KAPYGYh----gSQWIAYDDVTSLGRKVELIKK-ENLLGAMFWAIDLDDFGNv-CGq-gAHPLMGAVRYML 375
gi 15292287   426 KVPYLVd----gDQWVGFDDERAIRNKMHWIKS-NGFGGAMVWTIDMDDFKGevCGgnvKYPLIGAMREEL 491
gi 15292287   856 QVPFAYr----gNQWVGFDDERSLKTKTEWLKE-QGFGGIMVWSIDMDDFSGr-CGs-gKYPLLTALNDEL 919
gi 22003996   775 MVPYAYk----dDQWVGFDDQRSLKLKVQWLKQ-AGYGGVMVWSVDLDDFKGt-CTg-hSYPLLTAIKEEL 838
gi 22003996   347 LVPYAYl----gNQWVGFDDERSIRAKMQWIKM-NGYAGAMVWTVDMDDFRGr-CTt-kTWPLIGAMAEEL 410
gi 92110432   322 QTPFFVq----eNIWVGFDDQLSIYTKVNDLVIsKQLGGAMIWALDFDDFNNi-CGy-gKYPISRVMTDTL 386
gi 156382333  330 NAPYGYk----gKDWIGFDDPNSLVYKIDNVVKkNQLRGVMFWAIDLDDFSGehCGq-gKYPLMSAVKNYL 395
gi 156408091  320 RAPYGYvkqdwaDVWVGYDDERSLQLKVEEVIKaKGLAGAMFWALDLDDFDGssCGk-gNYPLMNAVKKYL 389
gi 167830427  342 MAPAVAv----gDQWISFDDVNSIEYKINYMKS-LGLGGTMVWAVDNDDFQAt-CGy--KNHLLRQMYFLL 404

| Disclaimer | Privacy statement | Accessibility |
NCBI Home NCBI Search NCBI SiteMap